1. Field of the Invention
The invention pertains to the field of lifting devices, such as handles and the like, that are used to carry equipment from one point to another. More specifically, the handles may be selectively attached to electrical equipment and detached once the electrical equipment is installed, for example, in a sliding rack assembly where the attached handles protrude to interfere with sliding motion of the rack assembly.
2. Discussion of the Related Art
In commercial and research facilities, electronic equipment or instrumentation is commonly housed in boxes or chassis that are mounted in electrical equipment racks having standard dimensions. Each rack, according to United States industry standards established by the Electronic Industries Association (EIA), typically has dimensions of approximately seventy-two inches in height, twenty-seven inches in depth, and nineteen inches in width, which corresponds to a rack volume of about 21.4 cubic feet. Standards in other countries may differ. Roller slides are used to hold instruments in a stacked arrangement on the racks and to facilitate movement of each unit out of alignment for replacement, servicing and/or modification. Rack-mounting of equipment in this manner advantageously provides a compact, easy to maintain implementation in a common duty area. Due to dimensional standardization of dimensions, it is difficult to sell non-standard sized commercial or research equipment where the equipment fails to comply with standard dimensions because the equipment cannot be used in the EIA racks.
Electronic equipment manufacturers provide increasing levels of functionality from internal components that have smaller sizes. From time to time, system designers may find it desirable to offer a chassis having a maximum width dimension to incorporate more internal components; however, the equipment can also be quite heavy and may require handles for lifting purposes. Because the rear of the chassis may be inaccessible for lifting purposes and because ergonomics may preclude the attachment of handles to the front of the chassis, handles are sometimes most conveniently located on the sides of the chassis across the width dimension. These handles may protrude to a greater width dimension than does the overall chassis. A problem arises when the handles interfere with sliding motion of the roller-slide assembly by abutting vertical support members of the equipment rack.
U.S. Pat. No. 5,505,533 discloses a rackmount chassis that adapts a standard personal computer for rack usage by encapsulating the personal computer. A handle is built into the side of the chassis for lifting of the assembly. The handle is formed of a dual-pivoting assembly in which the grasping portion of the handle that pivots on its axis of elongation. At least four pivoting operations are required to deploy the handle for lifting operations. Due to the positioning of his handle, the lifting operations are ergonomically incorrect, as the lifter""s strength and grip are significantly compromised due to the twisting and bending motion of the wrist. This weakening occurs because the lifter""s hand must engage the side-mounted handle in a handshake configuration as the lifter pushes the chassis forward.
Handles for lifting of electronic equipment cease to be a mere convenience and become a necessity when heavier items are being installed. For example, network server packages can weigh from one hundred to five hundred pounds (45 to 230 kilograms). Team lifting of these heavier items is a necessity. In some instances, the chassis that is being lifted contains sunken handholds that facilitate lifting. These handholds impose a burden that the wrists of the lifters are not optimally aligned with the chassis. The handholds also create a significant risk of personal injury to the lifters and/or damage to the equipment. In other instances, handles are temporarily attached to the chassis. The handles are removed after the equipment is installed, and storage is inconvenient because the loose handles are generally regarded as clutter until they are needed. It is a significant inconvenience that the handles often cannot be found when it is time to remove the chassis from the rack or to reposition the chassis in the rack. Detachable handles are usually not interchangeable between different chassis styles, such as chassis having different length dimensions, so it is also difficult to find substitute handles. When the handles cannot be found, there is significant risk of injury to the lifters or equipment damage in the attempt to move the chassis with improper lifting equipment.
There remains a need to provide a carry handle assembly that can be selectively attached and detached for use in lifting operations, yet are adjustable for convenient storage.
The adjustable carry handle assembly shown and described herein overcomes the problems outlined above by permitting selective adjustment to a plurality of overall lengths, for example, lengths that facilitate both lifting operations and convenience in storage. The carry handle assemblies may also be adjusted to a plurality of lengths for use in lifting a chassis of any length.
The carry handle assembly includes a first segment and a second segment that are telescopically interfitted in a manner that permits manual manipulation to achieve a plurality of overall lengths. The first segment contains at least one lengthwise receptacle, e.g., a channel, of sufficient dimensions for receiving at least part of the second segment. The second segment is at least partially received in the lengthwise receptacle to establish a telescoping interfit through which an overall length of the carry handle assembly can be adjusted by lengthwise shifting of the second segment within the lengthwise receptacle. At least one carry handle is attached to one of the first segment and the second segment. A mounting structure, such as pins, bayonet latches, clip fasteners, screws and bolts, is used for coupling the carry handle assembly with the chassis. The carry handle assembly may be attached for lifting purposes, removed, and adjusted to an overall length that permits storage on an electrical equipment rack.
The carry handle assembly may contain any number of handles. For example, a first handle may be attached to the first segment, and a second handle may be attached to the second segment. In this configuration, lengthwise shifting of the second segment within the lengthwise receptacle alters a length dimension between the first carry handle and the second carry handle. The carry handle assembly may be locked in a fixed length to prevent its removal from the chassis. Accordingly, threaded fasteners are not necessarily required to couple the carry handle assembly to the chassis.
A latch mechanism, such as a threaded fastener or a spring biased barrel lock, may be mounted on the carry handle assembly to lock the first segment and the second segment in a fixed overall length. While the latch mechanism is not necessarily required, it prevents collapse of the telescoping first and second segments and may be used to selectively attach the carry handle assembly to the chassis solely by virtue of this extension, for example, as pins on either end of the carry handle assembly are driven into engagement with the chassis when the carry handle assembly is extended. The latch mechanism may operate, for example, through use of a spring biased barrel lock that thrusts a plunger through a first hole in the first segment and a second hole on the second segment when the first and second holes are aligned to permit passage of the plunger.
The adjustable carry handle assembly may include a carry handle that contains a pivoting handle having a range of pivoting motion over a vertical arc. Pivoting the handle over the arc selectively increases or decreases a width of the carry handle assembly. An abutment may be provided that limits the range of the arc, e.g., from about 0xc2x0 to 90xc2x0. Outward termination of the arc may occur, for example, at a point of maximum width, which is also the most favorable point of termination for lifting purposes
The mounting structure may optionally include a mounting structure abutment, such as a dogleg abutment, that requires mounting of the carry handle assembly in a predetermined orientation relative to the chassis. The dogleg abutment may, for example, be attached to one of the first segment and the second segment, and extend to a greater length dimension than the overall length dimension.
The mounting structure may also include a plurality of openings for receipt of pins. These openings may be oriented to receive the pins in a position where axes of elongation in the threaded fasteners are oriented in parallel with the overall length dimension of the carry handle assembly, such that extension of the carry handle assembly drives the pins into engagement with the chassis.
The aforementioned structure permits sliding the first segment and the second segment relative to one another to establish an overall length that is required for mounting the carry handle assembly on the chassis. The carry handle assembly may then be attached to the chassis through use of the mounting structure.